So modelling a massive chaotic system produces probabilistic forecasts, not absolute ones...and this is surprising?
Just like daily, 5 daily and weekly forecasts there are chaotic variations, but it is far better than nothing. Do you turn your headlights off just because they don't illuminate the path all the way home?
The main GW predictions have been for increased extremes and the potential of tipping points for *really* big changes....which are playing out slightly faster then expected.
Those folks crowing about our cool summer should look at the northern hemisphere. Temperature records are tumbling at an ever-increasing rate.

For those that want some real background on climate record:
http://www.bom.gov.au/climate/change/acorn-sat/
Here you can get the data and an explanation of the homogenisation process: why and what is done. BTW. homogenisation does not change the trend...only the details of the variations which allows analysis of dynamics and major climate drivers.

As for response: We need to adapt to a chaotic world anyway, so we may as well take the best predictions on climate as input. The *real* issue is one of cheap energy from CO2 emitters...but it's easier to attack the complex science than it is to discuss complex socio-economic trade-offs.

Ambient temperature usually refers to the recordable air temperature. The cause 90 million years ago, well before the rise of humanity or any of our ancestors, was worldwide volcanic activity; possibly caused by periodic magnetic pole shifts?
[Currently, the Magnetic north pole is racing toward Siberia; at around 50 klms per annum, almost equivalent to light speed; in comparison, given the incredible viscosity of the liquid magma!]
The Co2 induced rise was around 2C? This was enough to melt the then frozen methane trapped in the tundras or under continental shelves?
This additional greenhouse effect added around another 3C to the ambient temperatures, making a total increase of 5C.
This was enough to induce a worldwide catastrophic event; that all but destroyed all life.
We know this because of the Mother Hubbard Palaeontologic record for around 90 million years ago or virtually empty cupboard, [rock strata,] bare of any bones or fossil record.
There are some exceptions, namely fish fossils, which given their location; and very stable geology, indicated ocean rises of around 70 metres during or just after; this particular extinction event.
If we don't act to keep ambient temperatures from rising by 2C, we can expect the frozen methane currently trapped beneath the tundras and elsewhere, to again melt adding at least a further 3C to ambient temps.
Creating a total rise of at least 5C by as soon as 2070; and a repeat of the climate conditions; that all but eliminated all life 90 million years ago; and indeed, an ice melt capable of causing ocean rises of or up to 70 metres.
A rise of this magnitude, would wipe out every Australian state capital city and at least 70% of our economy! I hope that addresses all of the questions or objections? Rhrosty.

Rhrosty, would you mind providing a link or two?

Rather than question the veracity of your alarming claims, particularly on an 'opinion site', I prefer to go to the primary sources. Thanks.

Links? Try the technical library of any good university! We had history/geology etc/etc books, well before we had computers; but, anyone who is able to Google is free to do their own research; rather than simply scoff or try to impune.
When I had two good eyes I could read two such books any day of the week; and indeed, retain much of the information.
That is a gift, which doesn't make me any better than any other poster; but, likely better informed?
Perhaps those who want to cast doubt; you know; those that are still stupid enough to buy coastal land or shares in coal companies, who have a clear and present interest in denying any and all evidence; that conflicts with their personal investment strategies, will use any chance to confuse or obfuscate?
I routinely insure my house and contents against fire, flood and earthquakes etc. not because they are ever present dangers or particularly likely, but because of the precautionary principle!
There have been a number of near complete extinction events in our planet's history.
A very wise person would study them in order to stop history repeating.
We humans also have a history of simply shooting the messenger; but particularly, when the message conflicts with our wishes or belief system; or indeed, our potential prosperity.
We need to be able to look our children and their children in the eye and confirm; that in truth, we did everything possible and within our power; to secure a safe and prosperous future for them; and indeed, follow the example of our own parents and their parents; and leave behind a better, brighter and more prosperous future for them and their kids; than that which they/we in their/our turn inherited!
I'm all right Jack greed/extreme conservative politics, [Tea party advocates,] unregulated free markets etc/etc; and or, manifest abysmal ignorance; or a dehumanizing lack of sensitivity or empathy, won't cut or create it!
Parenthetically, very low water use algae farming, could well save our coal industry and perhaps the planet! Rhrosty.

You know Rhrosty, I believe you are very passionate about what you say, and how you say it. However, it does not help your cause by being overly ‘alarmist’ in what you say, and how you say it.

There are extremists on both sides of the ‘climate divide'; the so called ‘sceptics’ (not in the scientific sense) and the so called ‘alarmists’. Without doubt, their passion is mostly driven by political ideology, religious doctrine, or socio-cultural belief – not science.

Indeed, it is very disheartening to have every Tom, Dick and Harry tell the real experts they don’t know what they are talking about, because … wait for it … they googled something or read it in the library. Don't get me wrong, the internet is great for gaining knowledge and the university libraries are the bastion of published research - but working at the coal-face (pun intended) does have its advantages, not least working from first principles.

This morning I had the chance to go over some of my previous comments on OLO (thanks to some spinner that's been apparently watching and counting my comments). While I won't reveal my real identity here (for what would be obvious reasons if it did become known), I am a practicing 'climate scientist', with some 30+ years’ experience in a very specialised field. I also understand that because I comment here under a pseudonym, my comments here have less credential, and less impact - so be it.

Nevertheless, I strongly support the contention that human activity is having a significant impact on the planet's climate and we (humanity) must not only adapt to the changing climate, but also take steps to move towards an alternative (to fossil fuels) energy future. It will take time and perseverance.

Rhrosty, it is very disturbing that reasoned and rational debate about global warming is being torpedoed by fake sceptics on the one hand and alarmists on the other. I humbly suggest you temper your passion.

A PRECAUTIONARY TALE

"Proponents of the precautionary principle are trying to smuggle in a default position: the environment trumps all other values. The key element of the principle is that it requires the taking of anticipatory action in the absence of scientific certainty. Note that, in the case of climate change, the trigger is not scientific certainty that CO2 emissions will have any impact on Earth's climate, or whether that impact will affect the environment in any measurable way. It is only the possibility that something bad might happen."

http://thegwpf.org/the-climate-record/2735-precautionary-principle-power-grab.html

Scientific knowledge does not advance by appealing (like Rhorsty) to the (pseudoscientific) Precautionary Principle in its many guises (bogus analogies, red herrings, risk "insurance", subjective "probabilities", personal fears, etc)

It does not advance AT ALL if statements and hypotheses claimed to be scientific are, in a fundamental sense, unfalsifiable and untestable; where what are often merely descriptions of changing natural phenomena ("climate change") masquerade as causal explanations and are promoted ($$$) as such by too many folk who should know better.

Beware of tricks that deliberately mingle (some) scientific knowledge with (a lot of) speculation. Just as religion should not pass itself off as a science, so too science should resist the temptation to morph into a religion, promoting apocalyptic warnings, tipping points, etc, especially when its arguments, hypotheses, "proofs", etc, are muddled, confused,inadequate, "complex", ad hoc, etc.

Alice